Ozone flux to Picea sitchensis (Bong) Carr and Picea abies (L) Karst during short episodes and the effects of these on transpiration and photosynthesis

Sitka spruce and Norway spruce were grown in controlled environments and then exposed to ozone (O3) for short periods as in mid-afternoon episodes experienced in the forest. For concentrations of between 20 and 300 nl litre(-1) there were linear relationships between exposure concentration and O3 uptake rates. Increasing photon flux densities increased rates of photosynthesis and transpiration, the increases being larger in actively growing than dormant seedlings. Physiological condition (dormancy or active growth), species and photon flux density were found to influence O3 flux via their effects on stomatal conductance. Exposure to 80 nl litre(-1) O3 resulted in consistent increases of stomatal conductance and there were also indications that water-use efficiency was decreased.     

Variability in ultraviolet total optical depth during the Southern California Ozone Study (SCOS97)

Formation of photochemical air pollution is governed in part by the solar ultraviolet actinic radiation flux, but wavelength-resolved measurements of UV radiation in polluted urban atmospheres are rarely available. As part of the 1997 Southern California Ozone Study, cosine weighted solar irradiance was measured continuously at seven UV wavelengths (300, 306, 312, 318, 326, 333 and 368 nm) at two sites during the period 1 July to 1 November 1997. The first site was at Riverside (260 m a.s.l.) in the Los Angeles metropolitan area, which frequently experiences severe air pollution episodes. The second site was at Mt Wilson (1725 m a.s.l.), approximately 70 km northwest of Riverside, and located above much of the urban haze layer. Measurements of direct (i.e., total minus diffuse) solar irradiance were used to compute total atmospheric optical depths. At 300 nm, optical depths (mean±1 S.D.) measured over the entire study period were 4.3±0.3 at Riverside and 3.7±0.2 at Mt Wilson. Optical depth decreased with increasing wavelength, falling at 368 nm to values of 0.8±0.2 at Riverside and 0.5±0.1 at Mt Wilson. At all wavelengths, both the mean and the relative standard deviation of optical depths were larger at Riverside than at Mt Wilson. At 300 nm, the difference between the smallest and largest observed optical depths corresponds to over a factor 2 increase in the direct beam irradiance for overhead sun, and over a factor 7 increase for a solar zenith angle of 60°. Principal component analysis was used to reveal underlying factors contributing to variability in optical depths. PCA showed that a single factor (component) was responsible for the major part of the variability. At Riverside, the first component was responsible for 97% of the variability and the second component for 2%. At Mt Wilson, 89% of the variability could be attributed to the first component and 10% to the second. Dependence of the component contributions on wavelength allowed identification of probable physical causes: the first component is linked to light scattering and absorption by atmospheric aerosols, and the second component is linked to light absorption by ozone. These factors are expected to contribute to temporal and spatial variability in solar actinic flux and photodissociation rates of species including ozone, nitrogen dioxide, and formaldehyde.     

A 3 year study of the aerosol in northwest Saxony (Germany)

Over three years (1993–1995) daily PM-10 aerosol samples were collected at two locations in Saxony, at the rural measurement station Melpitz and at the north-eastern border of Leipzig. By using ion chromatography the water soluble ions Na⁺, NH⁺₄, K⁺, Mg²⁺, Ca²⁺, Cl^-, NO^-₃and SO^2-₄ were analysed daily. Soot was detected by reflectance measurement and gravimetric analysis. Major trends during this period were observed for soot, nitrate, sulphate and calcium. Some components had typical seasonal distributions, e.g. soot, nitrate and sulphate. The rural station Melpitz was influenced more strongly by the power plants at both sides of the Polish border than the urban area of Leipzig-Halle. During inversion periods, maxima of all aerosol components were measured. However, the highest concentrations during inversion periods decreased during the last years at both locations.     

An Evaluation of the Effects of Ozone Injury on Radial Growth of Ponderosa Pine (Pinus ponderosa) in the Southern Sierra Nevada

Growth of ponderosa pines with visible symptoms of ozone injury was compared with that of asymptomatic trees in the southern Sierra Nevada, California. Time series analysis indicated that there was no significant reduction in annual radial increment of symptomatic trees during recent years compared to past growth and growth of asymptomatic trees. First order autocorrelation and climatic variables accounted for a large proportion of the variance in growth index, and winter precipitation was positively correlated with growth for all size and age classes. Although ozone concentrations are high enough to cause chlorosis and premature needle senescence in ponderosa pine, there has been no significant change in growth associated with ozone injury.     

The impact of the 2005 Gulf hurricanes on pollution emissions as inferred from Ozone Monitoring Instrument (OMI) nitrogen dioxide

The impact of Hurricanes Katrina and Rita in 2005 on pollution emissions in the Gulf of Mexico region was investigated using tropospheric column amounts of nitrogen dioxide (NO₂) from the Ozone Monitoring Instrument (OMI) on the NASA Aura satellite. Around New Orleans and coastal Mississippi, we estimate that Katrina caused a 35% reduction in NO_x emissions on average in the three weeks after landfall. Hurricane Rita caused a significant reduction (20%) in NO_x emissions associated with power generation and intensive oil refining activities near the Texas/Louisiana border. We also found a 43% decrease by these two storms over the eastern Gulf of Mexico Outer Continental Shelf mainly due to the evacuation of and damage to platforms, rigs, and ports associated with oil and natural gas production.     

Emission Reductions Needed to Meet the Standard for Ozone in Southern California: Effect of Boundary Conditions

Abstract

Combinations of total reactive organic gas (ROG) and nitrogen oxide (NO_x) emissions that do not exceed the National Ambient Air Quality Standard (NAAQS) for ozone for the meteorological conditions of the August 26-28, 1987 SCAQS episode, have been determined using the California Institute of Technology (CIT) photochemical air quality model. The sensitivity of these combinations to pollutant boundary conditions is examined.     

Distribution of polycyclic aromatic hydrocarbons (PAHs) and tributyltin (TBT) in Barcelona harbour sediments and their impact on benthic communities

Sediments have long been recognised as a sink for many contaminants like polycyclic aromatic hydrocarbons (PAHs) and tributyltin (TBT), which by virtue of their nature can strongly adsorb onto sediments affecting the benthic community inhabiting them. Using geographical information systems, this study reports and combines the results of several already existing studies along Barcelona harbour in order to assess the potential ecological impacts of these contaminants on the benthos of the harbour ecosystem. Chemical analysis indicated low to moderate contents of PAHs and high contents of TBT in sediments in Barcelona harbour. Comparison against existing sediment quality guidelines (SQGs) indicated that acutely toxic effects would not be expected for PAHs but for TBT, which represents a serious environmental threat for the benthic community. Benthos surveys revealed a deterioration of the benthic community throughout the harbour, especially in the inner port.     

Anthropogenic and natural influence on the PM(10) and PM(2.5) aerosol in Madrid (Spain). Analysis of high concentration episodes

Non-mineral carbon is the main component of PM10 and PM2.5 at an urban roadside site in Madrid accounting for more than 50% of the total bulk mass in winter pollution episodes. In these cases a 70-80% of the particle mass is anthropogenic. Particles of crustal/mineral origin contribute significantly to the observed PM10 concentrations, especially in spring and summer. They have also been found in the PM2.5 fraction although secondary particles are the next most important contributor in this size. Long-range transport particle episodes of Saharan dust significantly contribute to exceedence of the new daily limiting PM10 value in the urban network and at nearby rural background stations. This type of long-range transport event also influences PM2.5 concentrations. The crustal contribution can account for up to 67 and 53% of the PM10 and PM2.5 bulk mass in such cases.     

Nutrient pathways and their susceptibility to past and future change in the Eurasian Arctic Ocean

Climate change is altering nutrient cycling within the Arctic Ocean, having knock-on effects to Arctic ecosystems. Primary production in the Arctic is principally nitrogen-limited, particularly in the western Pacific-dominated regions where denitrification exacerbates nitrogen loss. The nutrient status of the eastern Eurasian Arctic remains under debate. In the Barents Sea, primary production has increased by 88% since 1998. To support this rapid increase in productivity, either the standing stock of nutrients has been depleted, or the external nutrient supply has increased. Atlantic water inflow, enhanced mixing, benthic nitrogen cycling, and land–ocean interaction have the potential to alter the nutrient supply through addition, dilution or removal. Here we use new datasets from the Changing Arctic Ocean program alongside historical datasets to assess how nitrate and phosphate concentrations may be changing in response to these processes. We highlight how nutrient dynamics may continue to change, why this is important for regional and international policy-making and suggest relevant research priorities for the future.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01673-0.     

Ozone injury on cutleaf coneflower (Rudbeckia laciniata) and crown-beard (Verbesina occidentalis) in Great Smoky Mountains National Park

Incidence and severity of visible foliar ozone injury on cutleaf coneflower (Rudbeckia laciniata L.) and crown-beard (Verbesina occidentalis Walt.) were determined along selected trails at three locations in Great Smoky Mountains National Park during the summers of 2000 and 2001: Clingmans Dome, Cherokee Orchard Road and Purchase Knob. Cutleaf coneflower exhibited a greater amount of foliar injury than crown-beard each year of the 2-year study. Incidence and severity of injury was significantly greater for cutleaf coneflower growing near the edge of the Clingmans Dome trail than in the interior of the stand. Injury was greater at Clingmans Dome than Purchase Knob (70% vs. 40% ozone-injured plants, respectively), coincident with greater ozone exposures. In contrast to Clingmans Dome, there were no differences in injury between plants growing near- and off-trail at Purchase Knob. Differences in sensitivity to ozone were not observed for crown-beard growing near the edge compared with the interior of the stand adjacent to the Cherokee Orchard Road Loop. Ozone injury was greatest on the lower leaves for both species sampled with over 95% of the injured leaves occurring on the lower 50% of the plant. This is the first report of foliar ozone injury on these plant species in situ, in the Park, illustrating the great variability in symptom expression with time, and within and between populations.     

Summary report of the corech (COGAR) workshop on the evaluation of air pollution episodes and associated control measures

Discussions within COGAR during 1981 indicated that collective information on the types of meteorological conditions when large, single sources like power stations contributed to pollution episodes, the frequency with which they occurred and the implications for intermittent control procedures, was important to all member utilities. This paper summarizes the findings of a working group set up by COGAR to study these problems.The investigation was concerned with SO₂ episodes and how feasible it would be to reduce their intensity by such measures as a substitution of low sulphur fuel or switching generation to areas where the probability of an episode developing is less.There has been a considerable reduction in SO₂ emissions in most urban areas in the last two decades. Nevertheless, in many locations, 24-h air pollution episodes can still be attributed to small or medium-sized emissions from low or medium level stacks, rather than to power stations and other large industrial sources with tall stacks. The worst cases in flat terrain where power stations do contribute for many hours are either stagnant conditions persisting for 24 h or a steady wind blowing consistently from an area containing several power stations. Single stations can present problems when topography interferes with dispersion or the stack height is inadequate for the emissions.Data on the frequency with which episodes occur in a given location and the ability to forecast episode conditions in advance, so that if appropriate, preventative measures may be taken, are the desired objectives. Achievement of these objectives requires a detailed understanding of the role of each type of source in relation to different meteorological situations and the local topography. The end product of such studies should be either;

• 1.(a) the specification of a procedure for implementing intermittent emission control
• 2.(b) a demonstration that intermittent control is not an effective option in the area under study.

In case (a), input data required are

• 1.(i) the vertical structure of the atmosphere
• 2.(ii) ground level concentrations of pollutant plus, in complicated topography
• 3.(iii) the three-dimensional distribution of pollutant.

COGAR is a group set up to coordinate atmospheric research in the electrical supply industry in Europe.     

Integrated Assessment Modeling of Atmospheric Pollutants in the Southern Appalachian Mountains. Part I: Hourly and Seasonal Ozone

Abstract

Recently, a comprehensive air quality modeling system was developed as part of the Southern Appalachians Mountains Initiative (SAMI) with the ability to simulate meteorology, emissions, ozone, size- and composition-resolved particulate matter, and pollutant deposition fluxes. As part of SAMI, the RAMS/EMS-95/URM-1ATM modeling system was used to evaluate potential emission control strategies to reduce atmospheric pollutant levels at Class I areas located in the Southern Appalachians Mountains. This article discusses the details of the ozone model performance and the methodology that was used to scale discrete episodic pollutant levels to seasonal and annual averages. The daily mean normalized bias and error for 1-hr and 8-hr ozone were within U.S. Environment Protection Agency guidance criteria for urban-scale modeling. The model typically showed a systematic overestimation for low ozone levels and an underestimation for high levels. Because SAMI was primarily interested in simulating the growing season ozone levels in Class I areas, daily and seasonal cumulative ozone exposure, as characterized by the W126 index, were also evaluated. The daily ozone W126 performance was not as good as the hourly ozone performance; however, the seasonal ozone W126 scaled up from daily values was within 17% of the observations at two typical Class I areas of the SAMI region. The overall ozone performance of the model was deemed acceptable for the purposes of SAMI’s assessment.     

Ozone uptake (flux) as it relates to ozone-induced foliar symptoms of Prunus serotina and Populus maximowiziixtrichocarpa

Field studies were conducted during 2003 and 2004 from early June to the end of August, at 20 sites of lower or higher elevation within north-central Pennsylvania, using seedlings of black cherry (Prunus serotina, Ehrh.) and ramets of hybrid poplar (Populus maximowiziixtrichocarpa). A linear model was developed to estimate the influence of local environmental conditions on stomatal conductance. The most significant factors explaining stomatal variance were tree species, air temperature, leaf vapor pressure deficit, elevation, and time of day. Overall, environmental factors explained less than 35% of the variation in stomatal conductance. Ozone did not affect gas exchange rates in either poplar or cherry. Ozone-induced foliar injury was positively correlated with cumulative ozone exposures, expressed as SUM40. Overall, the amount of foliar injury was better correlated to a flux-based approach rather than to an exposure-based approach. More severe foliar injuries were observed on plants growing at higher elevations.     

Lead impact on nutrition, energy reserves, respiration and stress protein (hsp 70) level in Porcellio scaber (Isopoda) populations differently preconditioned in their habitats

The impact of lead on food consumption, energy metabolism and the stress protein (hsp 70) level was investigated in the woodlouse Porcellio scaber (Isopoda), a common representative of the saprophagous soil macrofauna. To examine possible acclimation or tolerance to lead in woodlice from a contaminated habitat, animals of two populations, one deriving from a lead-contaminated artillery range and one from an uncontaminated control stand, were exposed to a series of lead concentrations under otherwise constant laboratory conditions for a maximum of 80 days. The applied lead concentrations (at a maximum 7945 mg/kg food dry wt) did not have any significant quantitative effect on the food consumption of the isopods, although the population pre-exposed in the artillery range showed a tendency toward a higher food uptake than the control population. After 80 days of exposure, both populations showed an equal trend toward increasing their respiration as lead concentrations, that they had been fed on, were increased. Accordingly, the glycogen content of the body, in both populations, was elevated with increasing lead concentrations in the food. This effect was more pronounced in the pre-exposed isopod population than in the one from the control stand. The non-pre-exposed isopods showed a general tendency toward a lower protein content of their bodies than the pre-exposed ones, although no effect of the lead on this parameter could be statistically proven. The ability of the artillery range isopods to synthesise stress proteins (hsp 70) in response to lead contamination decreased at much lower lead concentrations in their food than in the non-pre-exposed control population, even though the artillery range isopods seemed to be equally or even slightly better equipped with energy storage products. Even though the better nutrient status of these animals might refer to some lead tolerance of the pre-exposed population, the stress protein data suggest that a metal-resistant Porcellio population did not evolve in this lead-contaminated site.     

Elemental composition and nutritional value of the edible fruits of coastal red-milkwood (Mimusops caffra) and impact of soil quality on their chemical characteristics

In this study, the elemental distribution of essential and toxic elements in the soil and fruits of the indigenous plant species, Mimusops caffra, from ten sites along the KwaZulu-Natal east coast was investigated using inductively coupled plasma-optical emission spectrometry. This was done to determine the nutritional value of the fruits as well as to evaluate the impact of soil quality on elemental uptake by the plant. The elemental concentrations in the fruits (in descending order) were found to be K > Na > Ca > Mg > Si > Al > Fe > Zn > Mn > Ni > Cr > Cu > Pb > Mo > Sb > As > Se > V > Cd > Co. The results show that approximately 10 g of fruit would contribute more than 85% towards the recommended dietary allowance for Fe and Si for most adults. The proximate chemical composition revealed the fruits to contain approximately 84% moisture, 4.7% ash, 6.9% protein, 1.7% oil and 2.7% carbohydrates. The study indicates that the fruits of this indigenous plant species are a good source of essential elements with low levels of potentially toxic elements (Pb, As and Cd) which makes the plant a good indigenous food source especially for vulnerable communities that need food security.     

Assessment of the Streptomyces-plant system to mitigate the impact of Cr(VI) and lindane in experimental soils

Environmental Science and Pollution Research - Phytoremediation techniques have been proposed as ecological methods to clean up contaminated sites. This study is aimed to evaluate the effect of the...     

Effect of Nitrogen Nutrition on the Response of Tobacco to Ozone in the Atmosphere

Experiments were conducted to determine the effect of nitrogen nutrition on the response of tobacco to ozone in the atmosphere. With Nicotiana rustica L., a noncommercial tobacco, plants receiving an “optimum” nitrogen supply were found to be more susceptible to ozone injury than those receiving deficient or luxury supplies. Furthermore, it was found on analyses of the third oldest tobacco leaf that, while these “optimum” plants showed little or no increase in respiration as a result of ozone in concentrations too low to produce visible injury, plants grown with deficient or excess nitrogen showed a significant increase in respiration under these same conditions. The increase in respiration was accompanied by a comparable and equally significant decrease in carbohydrate con-lent in the latter plants which was not apparent in plants at the “optimum” nitrogen supply, as well as an increase in total nitrogen, protein-nitrogen, and amino-acid nitrogen. In conclusion, it is suggested that the carbohydrate reserve built up in plants grown with deficient nitrogen nutrition serves as protection against the ozidative potential of ozone. Likewise, a decrease in carbohydrate content below that of “optimum” plants provides protection in plants grown with an overabundance of nitrogen fertilization, though possibly by a more complex mechanism.     

Trace elements in organs and tissues of striped dolphins (Stenella coeruleoalba) from the Mediterranean sea (Southern Italy)

The distribution of metals (Cd, Cu, Zn, Fe, Cr, Pb and Sn) were investigated in various tissues and organs obtained from striped dolphins (Stenella coeruleoalba) stranded along the Apulian coasts (Southern Italy) during April-July 1991. Metals were determined by atomic absorption spectrophotometry. Metal concentrations were generally high in the liver, and low in brain and melon. Some metals showed organ-specific accumulations: copper, tin and zinc exhibited high concentrations in liver, the highest cadmium concentration was observed in kidney. Pathological, microbiological and parasitological surveys were performed on the animals. It was not possible to relate dolphin death to a specific cause, or to contaminants; however, the accumulation of metals may contribute to certain pathological alterations.     

On the way to cyanobacterial blooms: impact of the herbicide metribuzin on the competition between a green alga (Scenedesmus) and a cyanobacterium (Microcystis)

The hypothesis that exposure to a common and widely applied photosynthesis-inhibiting herbicide, metribuzin, would alter the outcome of the competitive battle between susceptible green algae (Scenedesmus obliquus) and tolerant cyanobacteria (Microcystis aeruginosa) was tested. In a long-term (17 d) experiment, Scenedesmus and Microcystis populations as well as mixtures that started with different inoculum composition (i.e. 3:1, 1:1 and 1:3 Scenedesmus:Microcystis) were grown in the absence or presence of metribuzin (100 microg l-1). In the absence of metribuzin, Scenedesmus was competitively superior and out-competed Microcystis regardless the initial composition of the mixed communities. However, this competitive outcome was reversed completely in the presence of metribuzin, where despite growth inhibition Microcystis became dominant. Hence, photosynthesis-inhibiting herbicides may not only affect algal community structure, but also provide cyanobacteria founder populations a window for dominance and thus play an important role in promoting cyanobacteria blooms.     

A multi-biomarker approach to assess the impact of farming systems on black tiger shrimp (Penaeus monodon)

This study examined the advantages of the use of biomarkers as an early warning system by applying it to different shrimp farming systems in Soctrang and Camau provinces, main shrimp producers in Mekong River Delta, Vietnam. Shrimp were collected at 15 different farms divided into four different farming systems: three farms were converted from originally rice paddies into intensive shrimp farming systems (IS1, IS2, IS3); three farms were rice-shrimp integrated farming systems (RS4, RS5, RS6); three farms were intensive farming systems (IS7, IS8, IS9); six farms were extensive shrimp farming systems (From ES1 to ES6). Lipid peroxidation (LPO) and total glutathione (GSH) were measured as well as catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and acetylcholinesterase activities (ACHE). Organ specificity was observed between gills and hepatopancreas with generally higher activity of GST in gills (GSTG) whereas the contrary was observed for LPO level in gills (LPOG). Hierarchical clustering and principal component analysis clearly indicated that shrimp reared in extensive culture system formed a distinct group from those reared in intensive or rice-shrimp integrated systems. CAT in gills (CATG), GPX in gills (GPXG) and hepatopancreas (GPXHP) and ACHE in muscle (ACHEM) of shrimp collected in extensive farms showed a general higher level than those in intensively farmed shrimp. On the contrary, we observed clear high levels of GSTG and GST in hepatopancreas (GSTHP) and LPOG and hepatopancreas (LPOHP) of shrimp sampled in intensive and rice-shrimp integrated systems. Thus, we propose that LPO and CAT, GPX, GST and ACHE can be used as a set of biomarkers for the assessment of health condition and can discriminate between shrimp cultivated in different farming systems. These findings provide the usefulness of integrating a set of biomarkers to define the health status of shrimp in different shrimp culture systems.